1. Field of the Invention
The present invention relates generally to footwear, and in particular the present invention relates to a customization system for footwear and to a composite plate in footwear outsoles.
2. Description of Related Art
Conventional articles of footwear include two primary elements: an upper and a sole structure. The upper is often formed of leather, synthetic materials, or a combination thereof and comfortably secures the footwear to the wearer's foot while also providing ventilation and protection from the elements. The sole structure generally incorporates multiple layers that are conventionally referred to as an insole, a midsole, and an outsole. The insole is a thin cushioning member located within the upper and adjacent the sole of the foot to enhance footwear comfort. The midsole, which is traditionally attached to the upper along the entire length of the upper, forms the middle layer of the sole structure and serves a variety of purposes that include controlling potentially harmful foot motions, such as over-pronation, attenuating ground reaction forces, and absorbing energy. The outsole forms the ground-contacting element of the footwear, and is usually fashioned from a durable material that includes texturing to improve traction.
In addition to the upper and the sole, a heel counter is often provided at the rear of the footwear. The heel counter is contoured to wrap around the user's heel and along the sides of the footwear to provide stability and support for the user's heel. The upper wraps around the rear exterior surface of the heel counter and is typically secured to the heel counter.
Shoes are typically manufactured with each portion of the shoe, the upper and the sole, prepared according to a standardized set of sizes. However, the size of a wearer's foot may not conform precisely to the standardized sizes, so customization of the shoe is desirable. Additionally, in high-performance settings, such as while playing a sport, it may be desirable to optimize the performance characteristics of the shoe, such as stability when turning, impact absorption, etc. One way to customize shoe fits is to use inserts.
Auger et al. (U.S. patent application publication number US 2006/0010718 A1, the entirety of which is incorporated herein by reference thereto) discloses an article of footwear having a heel counter attached to the upper with a removable heel pad which may be secured to the heel counter. The heel pad is used to help improve the fit about a user's heel. However, the customization of fit and performance in Auger et al. is limited to the heel section of the article of footwear.
In general, there is a need in the art for a system for customizing an article of footwear in both the heel region and along the length of the article of footwear. The use of such a system can allow for customization of fit or optimization for the use of the article footwear for a particular purpose, such as for playing a particular position in a sport.
In addition, modern footwear generally requires two competing and often contradictory demands: specific stiffness and reduced weight. Specific stiffness refers to stiffness per unit weight. Generally, increasing specific stiffness and durability requires additional material and, subsequently, additional weight. Reducing weight generally requires reducing material and in turn, sacrificing strength. To meet the need for increasing strength and durability, while at the same time, reducing weight, designers have proposed the use of composite materials, usually in the form of a composite plate.
While composite materials provide increased strength without increased weight, their use in articles of footwear has been difficult to implement and limited. The composite plate is usually only found in one portion of the footwear, usually either in the heel or the forefoot. Though partial composite plates provide the necessary structure in the desired region of the footwear while allowing the footwear to remain lightweight, full length composite plates have not been previously used as part of any type of athletic footwear. This is due to the particular structure of some composite materials, which often rupture or buckle under the stresses encountered during normal use. In particular, previous composite plates have been too rigid and inflexible, and could not be used where flexibility was required.
Vas (U.S. Pat. No. 6,425,193) discloses a full length composite plate that is composed of a metal matrix containing graphite and ceramic which is impregnated with a metal alloy. This sort of composite plate does not meet the requirement of being lightweight, as is most desirable in many types of footwear, including those used by athletes.
In general, there is a need for a lightweight full length composite plate that could be used as the primary structural component of various types of footwear. The desired full length composite plate would allow for maximum support in the heel and arch and provide proper structure and flexibility in the forefoot region, while at the same time, helping to maintain the desired weight reduction.